Method for generating double-speed IDR-unit for trick play, and trick play system and method using the same

• US 8,483,551 B2
• Filed: 12/03/2007
• Issued: 07/09/2013
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Jeong, Jin-Hwan, Lee, Yong-Ju, Kim, Hag-Young, Kim, Myung-Joon, Kim, Jung-Keun, Park, Choon-Seo, Min, Ok-Gee
• Primary Examiner(s): HARVEY, DAVID E
• Application Number:
  US11/949,746
• Publication Number:
  US 20080131078A1
• Time in Patent Office: 2,045 Days
• Field of Search: 386/343, 386/345, 725/90
• US Class Current: 386/345
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

Provided are a method for generating an instantaneous decoding refresh (IDR) unit for trick play, and a trick play system and method using the same. The trick play system includes: a speed information input unit configured to receive a speed value; a transmission condition determining unit configured to determine instantaneous decoding refresh (IDR) transmission conditions based on the speed value inputted through the speed information input unit; a double-speed IDR-unit generating unit configured to generate a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the transmission conditions determined by the transmission condition determining unit; and a transmitting unit configured to transmit the generated double-speed IDR-unit to an external user terminal.

Claims

1. A trick play system, comprising:

a transmission condition determining unit configured to determine instantaneous decoding refresh (IDR) transmission conditions based on a received speed value; and

a double-speed IDR-unit generating unit configured to generate a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the transmission conditions determined by the transmission condition determining unit;

wherein the double-speed IDR-unit generating unit receives total frames including an IDR frame and a plurality of prediction frames between the IDR frame and an immediately next IDR frame, removes a latter half of prediction frames from the total frames, and generates the double-speed IDR-unit with the remaining frames when a data size of the remaining frames is less than half of the data size of the total frames; and

wherein the double-speed IDR-unit generating unit removes frames referring to the removed prediction frames from the remaining frames.

2. The trick play system of claim 1, wherein the transmission condition determining unit determines transmission or skip of IDR-unit according to a value of (S/2−

1), where S represents the speed value.

3. The trick play system of claim 2, wherein the transmission condition determining unit determines to transmit the IDR-unit if the value of (S/2−

1) is equal to 0, and to skips as many as (S/2−

1) IDR-units after generation and transmission of the double-speed IDR-unit if the value of (S/2−

1) is not equal to 0.

4. The trick play system of claim 2, wherein the transmission condition determining unit determines to transmit the IDR-unit if the value of (S/2−

1) is equal to 0, and wherein the transmission condition determining unit subtracts “

1”

from the value of (S/2−

1) if the value of (S/2−

1) is not equal to 0, skips to a next IDR frame when the subtraction result value is not equal to 0, repeats the subtraction and the skip until the subtraction result value is equal to 0 and determines to transmit the IDR-unit.

5. The trick play system of claim 1, wherein the double-speed IDR-unit generating unit uses a stack to remove the latter half of the prediction frames in a reverse order.

6. A trick play method, comprising:

receiving a speed value;

determining instantaneous decoding refresh (IDR) transmission conditions based on the speed value;

generating a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the determined transmission conditions; and

transmitting the generated double-speed IDR-unit to a user terminal;

wherein the generating the double-speed IDR-unit includes;

removing a latter half of prediction frames from total frames ranging from a first IDR frame start position to the last prediction frame before a second IDR frame start position;

generating the double-speed IDR-unit with the remaining frames when a data size of the remaining frames is less than a half of the data size of the total frames;

removing frames referring to the removed prediction frames from the remaining frames; and

returning to the step of generating the double-speed IDR-unit.

7. The trick play method of claim 6, wherein the determining the transmission conditions includes determining IDR-unit transmission or skip according to a value of (S/2−

1), where S represents the speed value.

8. The trick play method of claim 7, wherein the determining the transmission conditions includes:

determining to transmit the IDR-unit when the value of (S/2−

1) is equal to 0; and

skipping as many as (S/2−

1) IDR-units after generation and transmission of the double-speed IDR-unit if the value of (S/2−

1) is not equal to 0.

9. The trick play method of claim 7, wherein the determining the transmission conditions includes:

determining to transmit the IDR-unit when the value of (S/2−

1) is equal to 0;

subtracting “

1”

from the value of (S/2−

1) when the value of (S/2−

1) is not equal to 0;

skipping to a next IDR frame when the subtraction result value is not equal to 0; and

repeating the subtraction and the skip until the subtraction result value is equal to 0 and determining to transmit the IDR-unit.

10. The trick play method of claim 6, further comprising:

removing frames referring to the removed latter half of prediction frames from the remaining frames; and

returning to the step of generating the double-speed IDR-unit with the remaining frames.

11. The trick play method of claim 10, wherein the removing the latter half of prediction frames includes:

removing the latter half of the prediction frames in a reverse order based on a stack.

12. A method for generating a double-speed instantaneous decoding refresh (IDR)-unit for trick play, the method comprising:

removing a latter half of prediction frames from total frames ranging from a IDR frame start position to the last prediction frame before a next IDR frame position; and

generating the double-speed IDR-unit with the remaining frames when a data size of the remaining frames is less than a half of the data size of the total frames;

wherein the generating the double-speed IDR-unit includes;

determining if the data size of the remaining frames is less than a half of the data size of the total frames;

additionally removing a latter half of frames from the remaining frames when the data size of the remaining frames is equal to or greater than a half of the data size of the total frames;

generating the double-speed IDR-unit with the remaining frames when the data size of the remaining frames is less than a half of the data size of the total frames;

removing frames referring to the removed prediction frames from the remaining frames; and

returning to the step of generating the double-speed IDR-unit.

13. The method of claim 12, wherein the removing the latter half of the prediction frames in a reverse order based on a stack.